Sutures and stitching are well known techniques for repairing body tissue after injury or surgery. Many types of surgery, such as gall bladder removal, hernia repair, and even coronary bypass surgery can now be performed through the techniques of endoscopic surgery. Endoscopic surgery, also referred to as laparoscopic surgery, minimally invasive surgery, or bloodless surgery, is performed through small incisions in the body with long slender cutting and grasping devices which can be inserted into the body through the small incisions. The devices have small working mechanisms on the distal end (the end of the instrument that is inserted into the body) and convenient handles and operating mechanisms (for controlling the working mechanisms on the proximal end). Surgeons use endoscopic scalpels and scissors for cutting tissue, endoscopic graspers and forceps for grabbing and manipulating tissue, and endoscopic suture needles for stitching tissue. Stitching a surgical or traumatic wound closed within an endoscopic work space requires quite a bit of manual dexterity and experience, and the final process of tying a knot in the stitching is very difficult.
Several devices have been suggested for assisting surgeons in securing the loose ends of a suture during open surgery. Rather than assisting the surgeon to tie a knot, the devices allow the surgeon to melt the two loose ends of the suture together or to create a melted mass on a single loose suture tip which prevents it from being withdrawn into the suture pathway. Zinnbauer, et al, Suture Cutting and Cauterizing Method Using Radiant Heat, U.S. Pat. No. 5,565,122 (Oct. 15, 1996), while not intended or adapted for endoscopic use, shows a device with jaws mounted at the distal end of a long neck, and a heating element over the jaws. When the jaws are laid against the skin, and the suture is place between the jaws, the heating element is heated to melt the suture and leave a melted mass of suture material on the suture. The melted mass prevents the suture from being pulled into and through the suture line. Polonsky, Suture Fusing and Cutting Apparatus, U.S. Pat. No. 4,662,068 (May 5, 1987) shows a pair of forceps with heat fusing surfaces on the grasping surfaces of the jaws. The forceps are used to grab and twist two loose suture ends and melt them together to secure the stitching.